Solve for $x$ and $y$ using substitution. ${-2x-2y = 4}$ ${y = x+12}$
Explanation: Since $y$ has already been solved for, substitute $x+12$ for $y$ in the first equation. ${-2x - 2}{(x+12)}{= 4}$ Simplify and solve for $x$ $-2x-2x - 24 = 4$ $-4x-24 = 4$ $-4x-24{+24} = 4{+24}$ $-4x = 28$ $\dfrac{-4x}{{-4}} = \dfrac{28}{{-4}}$ ${x = -7}$ Now that you know ${x = -7}$ , plug it back into $\thinspace {y = x+12}\thinspace$ to find $y$ ${y = }{(-7)}{ + 12}$ $y = 5$ You can also plug ${x = -7}$ into $\thinspace {-2x-2y = 4}\thinspace$ and get the same answer for $y$ : ${-2}{(-7)}{ - 2y = 4}$ ${y = 5}$